It's the symmetric property of identity inequality. The fundamentally incompatible axioms of some worldviews make communication nearly impossible in either direction, within a timeframe and level of effort most people are willing to expend.

There is no reasoning with people about specific issues when they are tied up in identity politics. That is true whether they are a liberal or a conservative.

No argument there.

However it gets a bit iffy when you accuse a certain group of people of identity politics.

Actually no, because 'those people' are the set of 'people who have chosen to label others as anti police' and a singular opinion isn't the same as a collective identity.

Admittedly people who hold that opinion might adhere to a 'conservative identity' but the gp was specifically describing people who engaged in categorical dismissal of of political proposal, so it's legitimate to say they can't be reasoned with because categorical dismissals are an example of a genetic fallacy.

The wording implies you can't reason with "those people", meaning the anti-anti-police ones. But it kinda misses the mark, because you can't reason with "anybody" active in the identity-politics environment that pervades the US.

Usually irony like this leads to a rediculous contradiction, but here it somehow all makes sense.